If there is ever a contest to pick which word has done the most damage to people's thinking, and to actions to carry out that thinking, my nomination would be the word "fair." It is a word thrown around by far more people than have ever bothered to even try to define it.
This mushy vagueness may be a big handicap in logic but it is a big advantage in politics. All sorts of people, with very different notions about what is or is not fair, can be mobilized behind this nice-sounding word, in utter disregard of the fact that they mean very different things when they use that word.
Some years ago, for example, there was a big outcry that various mental tests used for college admissions or for employment were biased and "unfair" to many individuals or groups. Fortunately there was one voice of sanity-- David Riesman, I believe-- who said: "The tests are not unfair. LIFE is unfair and the tests measure the results."